docs: def get_figuresize(fs, fsdef=(12,6),
                     orient='landscape', method='xrandr'):
      """ Generic function to return figure size in inches
  
          Useful for str-based flags such as:
              - 'a4'  : use orient='portrait' or 'landscape'
              - 'full': to get screen size
                  use method='xrandr' (recommended),
                  as 'xdpyinfo' tends to be wrong
      """
  
      assert fs is None or type(fs) in [str,tuple]
      if fs is None:
          fs = fsdef
      elif type(fs) is str:
          if fs=='a4':
              fs = (8.27,11.69)
              if orient=='landscape':
                  fs = (fs[1],fs[0])
          elif fs=='full':
              assert method in ['xrandr','xdpyinfo']
              if method=='xrandr':
                  cmd0 = "xrandr"
                  #cmd1 = "grep '*'"
                  out = subprocess.check_output(cmd0.split())
                  s = [o for o in out.decode('utf-8').split('\n') if 'mm x ' in o]
                  assert len(s)==1
                  s = [ss for ss in s[0].split(' ') if 'mm' in ss]
                  assert len(s)==2
                  fsmm = [int(ss.replace('mm','')) for ss in s]
              else:
                  cmd0 = 'xdpyinfo'
                  out = subprocess.check_output(cmd0.split())
                  s = [o for o in out.decode('utf-8').split('\n')
                       if 'dimensions' in o]
                  assert len(s)==1
                  s = s[0][s[0].index('(')+1:s[0].index(' millimeters')]
                  fsmm = [int(ss) for ss in s.split('x')]
              fs = (fsmm[0]/(10*2.54), fsmm[1]/(10*2.54))
      assert type(fs) is tuple and len(fs)==2
      return fs